posted on 2021-08-10, 14:09authored byBingbing Wang, Pan Peng, Wan Ma, Zhao Liu, Cheng Huang, Yangmin Cao, Ping Hu, Xiaotian Qi, Qingquan Lu
Herein,
a fast, scalable, and transition-metal-free borylation
of alkyl halides (X = I, Br, Cl) enabled by electroreduction is reported.
This process provides an efficient and practical access to primary,
secondary, and tertiary boronic esters at a high current. More than
70 examples, including the late-stage borylation of natural products
and drug derivatives, are furnished at room temperature, thereby demonstrating
the broad utility and functional-group tolerance of this protocol.
Mechanistic studies disclosed that B2cat2 serves
as both a reagent and a cathodic mediator, enabling electroreduction
of difficult-to-reduce alkyl bromides or chlorides at a low potential.